No power at heated door mirrors

[Stephen Hall]

Good evening-

 

I’m unfortunately at a bit of a loss. I recently picked up a 2005 Boxster S and am sorting through some of the small issues. One mystery is the fact that neither of the door mirrors are receiving current, but the rear window defroster is. The button for the rear defroster lights up and the rear window gets warm, but I checked the current across the connectors for both right and left mirror—nothing. Fault codes are also being thrown for both mirrors around the heating. Since both the rear window defroster and the mirror heating elements operate off the same switch, I’m assuming there must be a junction somewhere that I can look at? Any guidance would be greatly appreciated!

 

Steve

Edited September 14, 2020 by Stephen Hall
Corrected grammar

[Loren]

 

6689 – Door Mirrors
The door mirrors have been completely redesigned and represent a key element of the new exterior styling. The mirrors are connected to the mirror attachment point mount by way of a double arm. The design of the mirror housing has been revised, enabling the mirror glass to be positioned deeper inside the housing. The mirror glass itself is now
protected more effectively from turbulence and possible vibrations at high speeds.

Both door mirrors are electrically heated and adjustable and, in the case of fully electric sports seats or adaptive sports seats, are connected to the memory function. On request, both door mirrors and the interior rearview mirror can be provided with an automatic an anti-dazzle function (optional in combination with the rain sensor).

[Stephen Hall]

Thanks Loren! In my case, everything else is working. The mirrors can be positioned using the remote knob, the memory function works for different keys, and the passenger side mirror also dips down when the transmission is put into reverse. The only problem  am having is that both are no longer heating and are throwing fault codes when the rear demister button is pressed. As I said, I removed the glass from both sides, tested for voltage across the two connectors, and found none. What should the voltage be for these?

[Loren]

The mirror heating is part of the door control unit.

You may likely need a PIWIS tester to further diagnose or to reprogram the door CU.

[Stephen Hall]

On 9/14/2020 at 11:19 AM, Loren said:

The mirror heating is part of the door control unit.

You may likely need a PIWIS tester to further diagnose or to reprogram the door CU.

It does seem that way. I have gotten in contact with my local Indy Porsche shop; I will be bringing it in to have them hook it up to a PIWIS and see what’s going on. Thanks!